from typing import List

class Solution:
    def duplicateZeros(self, arr: List[int]) -> None:
        """
        Do not return anything, modify arr in-place instead.
        """
        i = 0
        while i < len(arr):
            if arr[i] == 0:
                arr.pop()
                arr.insert(i, 0)
                i += 2
            else:
                i += 1
    
    def duplicateZeros2(self, arr: List[int]) -> None:
        que = []
        for i in range(len(arr)):
            n = arr[i]
            que.append(n)
            if n == 0:
                que.append(0)
            arr[i] = que.pop(0)